Oil recovery

Abstract

A process for upgrading carbonaceous materials having low carbon content comprising preheating the carbonaceous material to a temperature above about 200 DEG C. in the absence of a solvent, extracting the heated carbonaceous material under moderate temperature and pressure conditions, and hydrotreating the extract under supercritical solvent conditions.

That which is claimed is: 
     
       1. A process for the recovery of hydrocarbons from oil shale containing said hydrocarbons comprising the steps of: (1) heating said oil shale to a temperature of at least about 200° C. and at a low to moderate pressure ranging from atmospheric to 200 psia in the absence of a solvent or diluent to effect at least partial decomposition of the kerogen and the release of a significant portion of the hydrocarbons from the oil shale,   (2) contacting the heated oil shale in a countercurrent manner with a hydrocarbon solvent comprising alkanes and cycloalkanes having from 4-10 carbon atoms and aromatic compounds selected from benzene, toluene, xylene, naphthalene, substituted forms thereof, and mixtures thereof at a pressure from about atmospheric to about 500 psia and a temperature in the range of from about 100° to about 300° F. (38°-150° C.) for about 10 to about 300 minutes to yield a hydrocarbon extract, and   (3) hydrotreating the hydrocarbon extract of step (2) under supercritical solvent conditions.   
     
     
       2. The process of claim 1 additionally comprising the step of: (4) recovering and recycling the solvent from step (3) to step (2).   
     
     
       3. The process of claim 2 wherein the solvent employed in step (2) is n-heptane or toluene or mixtures thereof. 
     
     
       4. The process of claim 3 wherein the solvent is toluene and the extraction takes place at a temperature of about 38° C. to about 150° C. 
     
     
       5. The process of claim 3 containing the additional step of: (4) recovering and recycling the solvent from step (3) to step (2).   
     
     
       6. The process of claim 4 including the additional step: (4) recovering and recycling the solvent from step (3) to step (2).   
     
     
       7. The process of claim 6 wherein the product of step (3) is further treated to yield a fuel. 
     
     
       8. The process of claim 7 wherein the process of step (3) is further treated to yield a lubricant. 
     
     
       9. A process according to claim 1 wherein preheating in step (1) is carried out at a temperature in the range of about 200° C. to 750° C. 
     
     
       10. A process according to claim 9 wherein preheating the step (1) is carried out at a temperature in the range of about 350° C. to 500° C. 
     
     
       11. A process according to claim 9 wherein the solvent is n-heptane or toluene or mixtures thereof.